1. Technical Field
The present disclosure relates to semiconductor devices and, more particularly, to semiconductor memory devices and methods of fabricating the same.
2. Description of Related Art
Semiconductor devices may be attractive to the electronics industry because of their small size, multi-function capabilities, and/or low fabrication costs. For example, high-performance semiconductor devices and/or low-cost semiconductor devices have experienced increased demand with the development of the electronics industry. In order to address these demands, semiconductor devices have become more highly-integrated. In particular, the integration density of semiconductor memory devices has increased to store more logic data.
A planar area occupied by a unit memory cell may directly affect the integration density of two-dimensional semiconductor memory devices. In other words, the integration density of the two-dimensional semiconductor memory devices may be influenced by a minimum feature size that relates to a process technology for forming fine patterns. However, there may be limitations in improving the process technology for forming the fine patterns. Additionally, high-cost equipment or apparatuses may be required to form the fine patterns. Thus, the costs of fabricating highly-integrated semiconductor memory devices may be relatively high. Three-dimensional semiconductor memory devices have been proposed to address some of the above limitations.